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Compared to the traditional wet-mate underwater power supply method, Magnetic Coupling Resonant Wireless Power Transfer (MCR-WPT) technology boasts advantages such as excellent insulation, high safety, and convenient operation, showing promising application prospects in the field of power supply for underwater vehicles and other mobile underwater devices. In order to explore the transmission characteristics of this technology underwater, this article first establishes a traditional mathematical model, and then modifies the underwater model through analysis of changes in coil self-inductance and mutual inductance, as well as the impact of eddy current losses. Using the modified mathematical model of the underwater MCR-WPT system, the transmission characteristics are analyzed, and simulations and experimental validations are performed using MATLAB R2022a software. In the study of frequency characteristics, it is found that the system operates optimally when both ends of the circuit work at the resonant state; that is, when finput = fresonance = 100 kHz, the output performance is at its best, and the optimal resonant frequency significantly improves power and transmission efficiency. When the input frequency is less than 87.3 kHz or greater than 122.9 kHz, the output power decreases to less than half of the maximum power. In the investigation of load effects, the optimal load for maximizing system output power was identified, but the load that maximizes transmission efficiency is different from this optimal load. This study provides strong theoretical support and guidance for improving the performance of underwater wireless power transmission systems. [ABSTRACT FROM AUTHOR]

Marine transportation is pivotal in the rapid development of global trade, significantly enhancing international economic and trade connectivity and impacting the sustainable development of the global economy. In this study, we developed a novel technical framework based on the Laplacian matrix to evaluate the node significance and edge connectivity of the global shipping network using 2019 vessel schedule data from the top 30 liner shipping companies, as ranked by Alphaliner. Our analyses were conducted in both L-space, characterizing the connectivity function, and P-space, characterizing the transfer function. The findings indicate the following. (1) There is no consistent relationship between node significance and centrality for most ports. Ports with high node significance are mainly located in the Asia–Pacific region, with Singapore Port being the port with the highest node significance in L-space and Shanghai Port being the port with the highest node significance in P-space. (2) In L-space, the structures with significant improvements in edge connectivity in the shipping network have at least one port node that exhibits both low degree centrality and low betweenness centrality; these are primarily found on East African routes. (3) In P-space, the structures with significant improvements in edge connectivity in the shipping network are more complex but are notably linked to the ports of Assaluyeh and Bandar Abbas in Iran. The proposed node evaluation and edge addition strategy effectively analyze port significance and edge connectivity, providing decision-making support for optimizing port layouts, supporting container route planning, and enhancing the overall performance of the shipping network. [ABSTRACT FROM AUTHOR]

Magnetically coupled resonant wireless power transfer (MCR-WPT) technology offers longer effective transmission distances and higher efficiency compared to traditional charging methods, making it better suited to the prolonged and efficient operation of autonomous underwater vehicles. This paper first establishes a traditional mathematical model and then refines it while analyzing the variations in the self-inductance and mutual inductance of underwater coils. To further enhance the system's performance, a multi-objective optimization of the coupling mechanism is conducted. An orthogonal experiment is employed to determine the effects of various influencing factors on the coils' self-inductance and mutual inductance. Subsequently, an RBF neural network is used to create a regression prediction model based on the results of the orthogonal experiment. The NSGA-II algorithm is then applied for the multi-objective optimization of the coupling mechanism, resulting in a Pareto front solution set. The optimized efficiency is 93.35%, representing an approximately 6% improvement over the original system, with the power density increasing from 1.267 × 10 6   W / m 3 before optimization to 4.782 × 10 6   W / m 3 after optimization. Significant enhancement in system performance is achieved. [ABSTRACT FROM AUTHOR]

The response characteristics of sound pressure level, displacement curve, longitudinal vibration and cuttings size of anchor bit during drilling in sandstone are studied by experiments. The experimental results showed that the sound pressure level and longitudinal vibration are larger during drilling in high strength sandstone, which is inversely proportional to cuttings grain and drilling speed. The decrease of drilling efficiency is more obvious when the abrasion bit is drilling in sandstone. Therefore, by optimizing the bit structure, the broken rock blocks can flow out of the anchorage hole as early as possible to avoid the accumulation of rock debris blocking the borehole and improve drilling efficiency.

This study considers a two-tier supply chain consisting of a fairness-neutral manufacturer and a fairness-concerned retailer. The manufacturer adjusts product quality and distributes the products through the retailer. The retailer sells the products to consumers having reference quality (RQ) effects that depend on the previously purchased product quality and change over time, and is assumed to have three, i.e., fairness neutral (FN), fairness-concerned with the status reference point (FSP) and fairness-concerned with the non-status reference point (FNSP), behaviors. The supply chain is modeled as a Stackelberg game wherein the manufacturer has the first mover advantage. The utility optimal control models with fairness concerns (FC) and RQ effects under FN, FSR and FNSR are developed using prospect theory, and are reformulated using the Hamilton-Jacobi-Bellman equations as tractable forms to derive the dynamic pricing and quality decisions. The results show that pricing and quality decisions are influenced by the FN, FSR and FNSR behaviors over time. The steady-state quality and wholesale price are, but the steady-state retail price is not, influenced by the fairness reference profit and the RQ. The manufacturer should cede some profit to the retailer with FC, especially when the retailer has the bargaining power. The FC is not always beneficial to the retailer. Numerical experiments are performed to examine the effects of the major parameters on the manufacturer and retailer utilities and to derive the managerial implications [ABSTRACT FROM AUTHOR]

Simple Summary: Ruminal microbiota plays an important role in the health and milk production of dairy cows. In this study, we found that high-concentrate diet (concentrate: forage = 60:40) feeding altered the composition of the microbiota in the rumen and produced toxic metabolites (LPS and histamine). The elevated concentrations of LPS and histamine in the gut were transferred into the bloodstream and caused damage to the ruminal and cecal walls. LPS and histamine stimulated an inflammatory response in the liver with the increased presence of H1 receptors. Our study provides a basis for exploring the impact of changes in gut microbiota composition on animal health and offers a novel therapeutic strategy for treating metabolic disorders caused by SARA. The ecosystem of ruminal microbiota profoundly affects the health and milk production of dairy cows. High-concentrate diets are widely used in dairy farms and evoke a series of metabolic disorders. Several studies have reported the effects of high-concentrate diets on the ruminal microbiome, while the effect of changes in ruminal microbial flora, induced by high-concentrate diet feeding, on the liver of dairy cows has not been studied before. In this study, 12 mid-lactating Holstein Friesian cows (weight of 455 ± 28 kg; parities of 2.5 ± 0.5; starting milk yield of 31.59 ± 3.2 kg/d; DMI of 21.7 ± 1.1 kg/d; and a DIM at the start of the experiment of 135 ± 28 d) were fitted with ruminal fistulas, as well as with portal and hepatic vein catheters. All cows were randomly divided into 2 groups; then, they fed with low-concentrate diets (LC, concentrate: forage = 40:60) and high-concentrate diets (HC, concentrate: forage = 60:40) for 18 weeks. The forage sources were corn silage and alfalfa hay. After the cows of two groups were euthanized over two consecutive days, ruminal microbiota; the concentration of LPS in the rumen content; cecum content; the levels of blood and histamine in rumen fluid, blood, and the liver; the histopathological status of the rumen and cecum; and the inflammatory response of the liver were assessed in dairy cows under conditions of subacute ruminal acidosis (SARA). These conditions were caused by high-concentrate diet feeding. All data were analyzed using the independent t-test in SPSS. The results showed that high-concentrate diet feeding increased the concentration of LPS and histamine in the rumen and plasma of veins (p < 0.05). The abundance of Bacteroidetes at the phylum level, and of both Bacteroidetes and Saccharibacteria at the genus level, was decreased, while the abundance of Firmicutes at the phylum level and Oscillibacter at the genus level was increased by high-concentrate diet feeding. The decreased pH values of ruminal contents (LC = 6.02, HC = 5.90, p < 0.05) and the increased level of LPS in the rumen (LC = 4.921 × 105, HC = 7.855 × 105 EU/mL, p < 0.05) and cecum (LC = 11.960 × 105, HC = 13.115 × 105 EU/mL, p < 0.01) induced the histopathological destruction of the rumen and cecum, combined with the increased mRNA expression of IL-1β (p < 0.05). The histamine receptor H1R and the NF-κB signaling pathway were activated in the liver samples taken from the HC group. In conclusion, the elevated concentrations of LPS and histamine in the gut may be related to changes in the ruminal microbiota. LPS and histamine induced the inflammatory response in the ruminal epithelium, cecum epithelium, and liver. However, the cause–effect mechanism needs to be proved in future research. Our study offers a novel therapeutic strategy by manipulating ruminal microbiota and metabolism to decrease LPS and histamine release and to improve the health of dairy cows. [ABSTRACT FROM AUTHOR]

As a function in organization and management, coordination is used to adjust the interrelation of the individuals in the organization in order to achieve the ultimate goal. Coordination can make individuals groups in a whole, reduce the contradiction and conflict between each other and promote the realization of the overall goal. The research on the coordination of relationship between the port industry of China and the growth of economy plays an important guiding role for the port industry and healthy development of national economy. According to the correlation model between port industry and economic growth, the correlation factor between port industry and economic growth is extracted, and the coordination indicator system of the relationship between the port industry and economic growth is established. Then, this article makes correlation analysis of the standardization of indicators, removes the bigger indicators of correlation coefficient and eliminates the impact of the duplication of information between indicators in order to simplify the indicator evaluation system. The actual results by data calculation show that there were six obvious changes in the coordination degree of the relationship between the port industry and economic growth in China during the period from 1990 to 2014.

To study the impact of Arctic routes on shipping networks, this paper uses an Arctic route system (ARS) model. Based on the evolution of the ARS, an improved weighted network evolution model (the BBV model) is used to predict the evolution of shipping networks from 2017 to 2035. Then, the multiple linkage analysis method is applied to extract the significant flows in the networks, and a competition network is built. The main results are as follows: (1) Significant flows in the maritime network under the influence of the ARS show an increasing trend and then a decreasing trend during evolution process. (2) According to multiple linkage analysis, Shanghai, Busan, and Tokyo have higher positions. (3) The overall network competition decreases. (4) In terms of the competitive landscape of China's container ports, Guangzhou has the strongest domestic competitive intensity. In addition, Chinese ports that face greater competition from foreign ports are always Shanghai and Shenzhen. One implication of analysis is that due to gradual influence of the ARS, port policy makers should implement different policies at different times. The paper also shows that some ports (such as Shanghai and Ningbo) should formulate cooperation agreements to promote ports development. [ABSTRACT FROM AUTHOR]

The Polar Silk Road (PSR) will open up China's maritime trade route through the Arctic to Northwest Europe and affect the freight function structure of China's coastal ports. This study evaluates ports' freight capacity and predicts the freight function structure of China's coastal ports under the PSR from four dimensions, namely, comprehensive/professional, function status, function scale and function hierarchy. The freight function structure is also compared with the current one. Results show that the ports in the Bohai Rim and Yangtze River Delta will have more diversified development and become the main force of the port system under the PSR. Coal will have an important position in most ports' cargo transportation under the PSR. The PSR will bring great economic development opportunities to the northern ports because of the influence of the sea route distance. The port function hierarchy is more obvious under the PSR, and the medium-sized ports are most affected by the PSR. We classify coastal portsaccording to the freight scale and freight function. An adaptive proposal for the government's port function planning is proposed in the conclusion. [ABSTRACT FROM AUTHOR]